Title. How FIFO is Your Concurrent FIFO Queue? Andreas Haas, Christoph M. Kirsch, Michael Lippautz, Hannes Payer. RACES Workshop, October 2012

Transcription

1 Title How FIFO is Your Concurrent FIFO Queue? Andres Hs, Christoph M. Kirsch, Michel Lipputz, Hnnes Pyer University of Slzurg RACES Workshop, Octoer /17

2 Strict vs. Relxed FIFO Queues strict FIFO queue implementtions relxed FIFO queue implementtions 2/17

3 Strict vs. Relxed FIFO Queues strict FIFO queue implementtions linerizle with respect to strict FIFO queue semntics relxed FIFO queue implementtions 2/17

4 Strict vs. Relxed FIFO Queues strict FIFO queue implementtions linerizle with respect to strict FIFO queue semntics relxed FIFO queue implementtions linerizle with respect to relxed FIFO queue semntics 2/17

5 Strict vs. Relxed FIFO Queues strict FIFO queue implementtions linerizle with respect to strict FIFO queue semntics relxed FIFO queue implementtions linerizle with respect to relxed FIFO queue semntics ounded out-of-order tretment of queue elements possile 2/17

6 Strict vs. Relxed FIFO Queues strict FIFO queue implementtions linerizle with respect to strict FIFO queue semntics relxed FIFO queue implementtions linerizle with respect to relxed FIFO queue semntics opertions/ms (more is etter) LB MS FC numer of threds ounded out-of-order tretment of queue elements possile 2/17

7 Strict vs. Relxed FIFO Queues strict FIFO queue implementtions linerizle with respect to strict FIFO queue semntics relxed FIFO queue implementtions linerizle with respect to relxed FIFO queue semntics opertions/ms (more is etter) numer of threds ounded out-of-order tretment of queue elements possile LB MS FC US k-fifo (k=80) 2/17

8 Strict vs. Relxed FIFO Queues strict FIFO queue implementtions linerizle with respect to strict FIFO queue semntics relxed FIFO queue implementtions linerizle with respect to relxed FIFO queue semntics opertions/ms (more is etter) numer of threds ounded out-of-order tretment of queue elements possile LB MS FC US k-fifo (k=80) RR Scl (p=80) 2RA Scl (p=80) 2/17

9 How FIFO re Relxed FIFO Queues? Some people sy relxed FIFO queues re not enough FIFO. No pplictions for relxed FIFO queues. 3/17

10 How FIFO re Relxed FIFO Queues? Some people sy relxed FIFO queues re not enough FIFO. No pplictions for relxed FIFO queues. We sy relxed FIFO queue implementtions cn e even more FIFO thn strict FIFO queue implementtions. 3/17

11 Exmple time 4/17

12 Exmple lineriztion point time 4/17

13 Exmple lineriztion point linerizle time 4/17

14 Exmple lineriztion point linerizle time time 4/17

15 Exmple lineriztion point linerizle time not linerizle time 4/17

16 Exmple lineriztion point out-of-order execution of overlpping opertions linerizle time out-of-order tretment of queue elements not linerizle time 4/17

17 Key Ide 1.) 2.) Record concurrent histories of vrious FIFO queue implementtions. Anlyze these concurrent histories using only the invoction times of opertions. 5/17

18 Key Ide 1.) 2.) Record concurrent histories of vrious FIFO queue implementtions. Anlyze these concurrent histories using only the invoction times of opertions. Idelly opertions would tke zero time 5/17

19 Key Ide 1.) 2.) Record concurrent histories of vrious FIFO queue implementtions. Anlyze these concurrent histories using only the invoction times of opertions. Idelly opertions would tke zero time Independent of the execution time of opertions 5/17

20 Element-Firness time 6/17

21 Element-Firness zero-time lineriztion time 6/17

22 Element-Firness element overtkes element zero-time lineriztion time 6/17

23 Element-Firness element overtkes element zero-time lineriztion time Definition element-firness = numer of overtkings in the zero-time lineriztion 6/17

24 Experiments ll threds do in prllel for itertions { ueue unique element ueue element } 7/17

25 Experiments ll threds do in prllel for itertions { ueue unique element clculte Pi ueue element clculte Pi } 7/17

26 Experiments ll threds do in prllel for itertions { ueue unique element clculte Pi ueue element clculte Pi } No ueues in the first 200 itertions to void empty checks No ueues in the lst 200 itertions to empty the queue. 7/17

27 Element-Firness per Element threds element-firness per element (logscle, less is etter) computtionl lod (logscle) 8/17

28 Element-Firness per Element threds element-firness per element (logscle, less is etter) computtionl lod (logscle) LB MS FC 8/17

29 Element-Firness per Element threds element-firness per element (logscle, less is etter) computtionl lod (logscle) LB MS FC US k-fifo (k=80) 8/17

30 Element-Firness per Element threds element-firness per element (logscle, less is etter) computtionl lod (logscle) LB MS FC US k-fifo (k=80) RR Scl (p=80) 2RA Scl (p=80) 8/17

31 Opertion-Firness Mesure the out-of order execution of single opertions 9/17

32 Opertion-Firness Mesure the out-of order execution of single opertions Oservtion: Lineriztion points induce strict order on the queue opertions 9/17

33 Opertion-Firness Mesure the out-of order execution of single opertions Oservtion: Lineriztion points induce strict order on the queue opertions time 9/17

34 Opertion-Firness Mesure the out-of order execution of single opertions Oservtion: Lineriztion points induce strict order on the queue opertions time 9/17

35

36 opertion overtkes opertion

37 opertion overtkes opertion Definition opertion-firness = numer of overtkings in concurrent history

38 Opertion-Age nd Opertion-Lteness Definition ge (op) = numer of opertions op overtkes 10/17

39 Opertion-Age nd Opertion-Lteness Definition ge (op) = numer of opertions op overtkes ge( ) = 0 ge( ) = 1 10/17

40 Opertion-Age nd Opertion-Lteness Definition ge (op) = numer of opertions op overtkes Definition lteness (op) = numer of opertions which overtke op ge( ) = 0 ge( ) = 1 10/17

41 Opertion-Age nd Opertion-Lteness Definition ge (op) = numer of opertions op overtkes Definition lteness (op) = numer of opertions which overtke op ge( ) = 0 ge( ) = 1 lteness( ) = 1 lteness( ) = 0 10/17

42 Experiments (2) Only for strict FIFO queue implementtions t the moment. Mesuring relxed implementtions is future work. 11/17

43 Experiments (2) Only for strict FIFO queue implementtions t the moment. Mesuring relxed implementtions is future work. ll threds do in prllel for itertions { ueue unique element clculte Pi } 11/17

44 Experiments (2) Only for strict FIFO queue implementtions t the moment. Mesuring relxed implementtions is future work. ll threds do in prllel for itertions { ueue unique element clculte Pi } one thred does ueue ll elements sequentilly 11/17

45 Mximum Opertion-Age threds mximum opertion-ge (logscle, less is etter) computtionl lod (logscle) LB MS FC 12/17

46 Mximum Opertion-Lteness threds mximum opertion-lteness (logscle, less is etter) computtionl lod (logscle) LB MS FC 13/17

47 Numer of Overtking Opertions % of ueue opertions with opertion-ge > 0 (less is etter) 80 threds computtionl lod (logscle) LB MS FC 14/17

48 Numer of Overtken Opertions % of ueue opertions with opertion-lteness > 0 (less is etter) 80 threds computtionl lod (logscle) LB MS FC 15/17

49 Conclusion We introduced metrics to compre the ehvior of vrious FIFO queue implementtions. Relxed implementtion cn pper more FIFO thn strict implementtions. Future work Mesure opertion-firness of relxed FIFO queue implementtions. Use element-firness to nlyze implementtion of other dt structures, e.g. stcks. 16/17

50 Thnk You Thnk You For more informtion out the queue implementtions see Additionl mesurement results cn e seen on 17/17